Re: Virtual Networking
On 10/25/22 17:03, Armin Lepir wrote:
Hi
I am using libvrt for the first time. Im building a KVM for multiple
Virtual OS instances.
The problem i have is with your official documentation for Virtual
Networking.
https://wiki.libvirt.org/page/VirtualNetworking
<https://wiki.libvirt.org/page/VirtualNetworking>
Please note that our wiki page is obsolete and we tried to move
everything into our knowledge base articles:
https://libvirt.org/kbase/
We're keeping the wiki around though, because maybe not everything was
moved.
The following is wrong:
The default mode is BRIDGE + NAT.
Optional mode is ROUTING.
It should be:
The default mode is ROUTING + NAT.
Optional mode is BRIDGE.
As far as i know a bridge operates on the Layer2.
IP and NAT operate on the Layer3.
NAT can not operate on the L2.
Please tell me that im wrong and explain how am i wrong.
If we'd be talking about bare metal network components then you are 100%
correct. Except, the Linux bridge is more than just plain L2 bridge. It
can have an IP address, route traffic, serve as network interface (when
a host is sending a packet to a guest, the packet is injected into said
bridge).
What the wiki page is trying to say, that by default you'll get this
'default' network which uses this Linux 'bridge' + NAT. Optionally, you
can define new network, or modify the existing one to switch to so
called routed mode.
Hope this clears things up.
Michal